TracingtheNormalM
yelin
ationPatternon
Neo
natalM
RIBrainIm
aging;from
BirthtoTwoYears.
DrSiné
adCu
lleton,DrC
lareRoche
,DrD
eclanShep
pard
Departmen
tofR
adiology,G
alwayUniversity
Hospital,Ire
land
Purpose
Afterbirththeim
maturepaed
iatricbrainun
dergoe
sfurthe
rmaturationandmostimpo
rtantly
maturationof
the
myelinated
structures
essentialfor
prop
agationof
impu
lseswhich
willallowno
rmalde
velopm
ent.Thisoccursina
step
wise
pred
ictablefashion.
Und
erstanding
theno
rmalprog
ressionof
myelinationcanavoidmisinterpretation
ofno
rmalchangesas
pathologyandalso
iden
tifypathologyaffectingtheno
rmalmaturationprocess.Disrup
tion
inthepred
ictedno
rmal
myelinationpatte
rnis
impo
rtantto
recognise
asmanyreferralsin
this
agearefor
investigationof
developm
entald
elay
orde
velopm
entalabn
ormality.T
hispo
ster
presen
tsasystem
aticapproach
torecognising
theexpe
cted
myelinated
structures
atanu
mbe
rofagesfrom
birthto
twoyears.
Discussion
Myelinationbe
gins
inutero.
Maturationis
pred
ominantly
completeby
2yearsof
agebu
tdo
escontinue
into
adulthoo
d.Theexpe
cted
progressioniscraniocaud
allyfro
mde
epto
superficial,fro
mpo
steriorto
anterio
r,with
sensoryproceeding
motor.The
major
changeso
ccurrin
ginchem
icalcompo
sitionaccoun
tfor
thechangess
eenon
T1andT2
imaging
1,2 .Thehigher
water
conten
tmeanthat
theT1
andT2
relaxatio
ntim
esarelonger
than
thoseof
anadultbrain.
Theserelaxatio
ntim
esshortenwith
maturation.
From
birthto
approxim
ately4-6m
onthsthe
norm
almyelinationpatte
rnisthereverseof
theadulta
ndwhite
matterisof
lower
signalthangrey
mattero
nT1
(Figure1)
andof
higher
signalonT2(Figure2)
1,3,4 .
Figure
1:T1-w
eighted
axialim
agefro
man
MRI
brain
ofan
11day
old
neon
ate.
Thegrey
matter
isof
lower
signalon
T1than
thesurrou
ndinggrey
matter.
Figure
2:T2-w
eightedaxialimage
from
anMRI
brainof
an11
dayold
neon
ate.
Thewhite
matterhe
reis
seen
ashype
rintense
tothe
surrou
ndinggrey
matter.
T1and
T2myelin
ationmileston
esterm
birth:
brainstem,cereb
ellum,posterio
rlim
bofth
einternalcapsule,optictract,pe
rirolandicregion
2-3mon
ths:anterio
rlim
bofth
einternalcapsule
3-4mon
ths:splenium
ofthe
corpu
scallosum
4-6mon
ths:genu
ofthe
corpu
scallosum
References
1.Ballesteros
M,H
ansenP,Soila
K.MRIm
agingof
thede
veloping
human
bran,part2
postnataldevelop
men
t.Radiograph
ics1
993;
13:611-622.
2.Yakovlev
Pl,Lecou
rsAR
.The
myelogenetic
cycleof
region
almaturationof
thebrain.
In:M
inkowskiA
,ed.
Region
alde
velopm
ento
fthe
brainin
early
life.
Philade
lphia,Pa:Davis
1967;3-69.
3.Ho
lland
BA,H
aasDK
,Norman
D,Brant-Z
awadzkiM,N
ewtonTH
.MRIof
norm
albrainmaturation.AJNR
1986;7:201-208.
4.BaierlP,ForsterC
h,Fend
elH,
NaegeleM,FinkU,
Kenn
W.M
agne
ticresonanceim
agingof
norm
alandpathologicalwhite
matterm
aturation.Paed
iatrRadio1988;18:183-189.
KnaapMS,ValkJ,Barkho
fF.M
agne
ticresonanceof
myelin
ationandmyelin
disorders.Sprin
gerV
erlag.(2005)
T2-w
eightedim
agesat6
mon
thss
howingmyelinationofth
esplenium
ofthe
corpu
scallosum.Image2at
10m
onthsandim
age3at2yearssh
owprogressiv
emyelinationinth
einternalcapsule,corpu
scallosum,
forcep
sminorand
forcep
smajor.
T1-w
eightedaxialimagesofan11dayoldneo
natesh
owingmyelinationinth
epe
ri-roland
icregion
,the
posteriorlim
bofth
einternalcapsuleand
brainstem.
T1isthemostsen
sitiv
eforchildren<1year
5
T2isthemostsen
sitiv
esequ
ence
forchildren>1
year
Itisim
portanttoun
derstand
theno
rmalprogressionof
myelinationto
iden
tifymyelinationabno
rmalities.
Attw
oyearsof
agethemyelinationpa
ttern
resembles
that
ofan
adult.Ho
wever,m
yelinationcontinue
sin
someareass
uchas
subcorticalwhite
matter1.
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